[ntp:questions] ntpd connect gpsd shared memory driver

Richard Cagley rcagley at gmail.com
Tue Jun 18 17:39:20 UTC 2013


On Tue, Jun 18, 2013 at 9:27 AM, Rob <nomail at example.com> wrote:

> As I wrote before, your ntp config is not correct.  please copy it
> from the docs.  However, that is not the cause of the problem.
> (it would be the cause of severe inaccuracy once you obtain NMEA data
> as you are not using PPS)
>

yeah, figured I'd walk before I ran so I tried to make my ntp.conf file as
simple as possible to at least get some timing info, which thanks to your
and AC's help I now have.

ok, now onto pps. I went here
http://gpsd.berlios.de/gpsd.html
...and am now using this as my ntp.conf
---
server 127.127.28.0 minpoll 4 maxpoll 4
fudge 127.127.28.0 time1 0.420 refid GPS
server 127.127.28.1 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.1 refid GPS1
---

But, sadly no pps sync...
---
/ # ntpq -p
     remote           refid      st t when poll reach   delay   offset
 jitter
==============================================================================
*SHM(0)          .GPS.            0 l    7   16  377    0.000    0.048
0.005
 SHM(1)          .GPS1.           0 l    -   16    0    0.000    0.000
0.000
---
I have pps debug output built into the kernel and can see pps events on the
console while I look at gpsd output
---
PPS event at 9862
PPS event at 9962
PPS event at 10062
PPS event at 10162
---

Sorry, this is so long, but here's a dump of the gpsd output. There are
several things that concern me, such as some of the warning, but not sure
of the severity

/ # gpsd -bn -N -D5 /dev/ttyO0
gpsd:INFO: launching (Version 3.7)
gpsd:IO: opening IPv4 socket
gpsd:INFO: listening on port 2947
gpsd:PROG: NTPD shmat(0,0,0) succeeded, segment 0
gpsd:PROG: NTPD shmat(32769,0,0) succeeded, segment 1
gpsd:PROG: NTPD shmat(65538,0,0) succeeded, segment 2
gpsd:PROG: NTPD shmat(98307,0,0) succeeded, segment 3
gpsd:PROG: shmat() succeeded, segment 131076
gpsd:PROG: shared-segment creation succeeded,
gpsd:PROG: PPS thread launched
gpsd:INFO: NTPD ntpd_link_activate: 1
gpsd:INFO: stashing device /dev/ttyO0 at slot 0
gpsd:PROG: no etc/gpsd/device-hook present, skipped running ACTIVATE hook
gpsd:INFO: opening read-only GPS data source type 2 and at '/dev/ttyO0'
gpsd:PROG: PPS Create Thread gpsd_ppsmonitor
gpsd:PROG: PPS chrony socket /var/run/chrony.ttyO0.sock doesn't exist
gpsd:INFO: PPS cycle: 631139111, duration: 631139111 @ 1371576962.280231
gpsd:INFO: speed 4800, 8N1
gpsd:PROG: Probing "Garmin USB binary" driver...
gpsd:PROG: Probe not found "Garmin USB binary" driver...
gpsd:PROG: Probing "GeoStar binary" driver...
gpsd:IO: Sent GeoStar packet id 0xc1
gpsd:PROG: Probe not found "GeoStar binary" driver...
gpsd:PROG: Probing "Trimble TSIP" driver...
gpsd:INFO: speed 9600, 8O1
gpsd:INFO: speed 4800, 8N1
gpsd:PROG: Probe not found "Trimble TSIP" driver...
gpsd:PROG: no probe matched...
gpsd:INFO: gpsd_activate(): activated GPS (fd 4)
gpsd:INFO: device /dev/ttyO0 activated
gpsd:INFO: running with effective group ID 0
gpsd:INFO: running with effective user ID 99
gpsd:INFO: startup at 2013-06-18T17:36:02.000Z (1371576962)
gpsd:PROG: switch_driver(Generic NMEA) called...
gpsd:PROG: selecting Generic NMEA driver...
gpsd:INFO: /dev/ttyO0 identified as type Generic NMEA (0.564143 sec @
4800bps)
gpsd:IO: <= GPS:
$GPRMC,173602.00,A,3425.96985,N,11951.97924,W,0.039,,180613,,,A*63
gpsd:DATA: merge_ddmmyy(180613) sets year 2013
gpsd:DATA: GPRMC: registers fractional time 173602.00
gpsd:DATA: RMC: ddmmyy=180613 hhmmss=173602.00 lat=34.43 lon=-119.87
speed=0.02 track=0.00 mode=2 status=1
gpsd:DATA: GPRMC time is 1371576962.000000 = 2013-06-18T17:36:2.00Z
gpsd:PROG: GPRMC sentence timestamped 173602.00.
gpsd:PROG: GPRMC starts a reporting cycle.
gpsd:DATA: packet type 1 from /dev/ttyO0 with
{ONLINE|TIME|LATLON|SPEED|TRACK|STATUS|MODE|PACKET|DRIVER|CLEAR}
gpsd:IO: <= GPS: $GPVTG,,T,,M,0.039,N,0.072,K,A*2C
gpsd:DATA: packet type 1 from /dev/ttyO0 with {ONLINE|PACKET}
gpsd:IO: <= GPS:
$GPGGA,173602.00,3425.96985,N,11951.97924,W,1,06,2.39,2.7,M,-33.5,M,,*6B
gpsd:DATA: GPGGA: registers fractional time 173602.00
gpsd:DATA: GGA: hhmmss=173602.00 lat=34.43 lon=-119.87 alt=2.70 mode=3
status=1
gpsd:DATA: GPGGA time is 1371576962.000000 = 2013-06-18T17:36:2.00Z
gpsd:PROG: GPGGA sentence timestamped 173602.00.
gpsd:DATA: packet type 1 from /dev/ttyO0 with
{ONLINE|TIME|LATLON|ALTITUDE|STATUS|MODE|PACKET}
gpsd:IO: <= GPS: $GPGSA,A,3,16,06,07,23,10,13,,,,,,,3.29,2.39,2.26*00
gpsd:PROG: GPGSA sets mode 3
gpsd:DATA: GPGSA: mode=3 used=6 pdop=3.29 hdop=2.39 vdop=2.26
gpsd:DATA: packet type 1 from /dev/ttyO0 with {ONLINE|MODE|DOP|PACKET|USED}
gpsd:IO: <= GPS:
$GPRMC,173603.00,A,3425.96981,N,11951.97923,W,0.039,,180613,,,A*61
gpsd:DATA: merge_ddmmyy(180613) sets year 2013
gpsd:DATA: GPRMC: registers fractional time 173603.00
gpsd:DATA: RMC: ddmmyy=180613 hhmmss=173603.00 lat=34.43 lon=-119.87
speed=0.02 track=0.00 mode=2 status=1
gpsd:DATA: GPRMC time is 1371576963.000000 = 2013-06-18T17:36:3.00Z
gpsd:PROG: GPRMC sentence timestamped 173603.00.
gpsd:PROG: GPRMC starts a reporting cycle.
gpsd:PROG: tagged GGA as a cycle ender.
gpsd:DATA: packet type 1 from /dev/ttyO0 with
{ONLINE|TIME|LATLON|SPEED|TRACK|MODE|PACKET|CLEAR}
gpsd:IO: <= GPS: $GPVTG,,T,,M,0.039,N,0.072,K,A*2C
gpsd:DATA: packet type 1 from /dev/ttyO0 with {ONLINE|PACKET}
gpsd:IO: <= GPS:
$GPGGA,173603.00,3425.96981,N,11951.97923,W,1,06,2.39,2.6,M,-33.5,M,,*68
gpsd:DATA: GPGGA: registers fractional time 173603.00
gpsd:DATA: GGA: hhmmss=173603.00 lat=34.43 lon=-119.87 alt=2.60 mode=3
status=1
gpsd:DATA: GPGGA time is 1371576963.000000 = 2013-06-18T17:36:3.00Z
gpsd:PROG: GPGGA sentence timestamped 173603.00.
gpsd:PROG: GPGGA ends a reporting cycle.
gpsd:DATA: packet type 1 from /dev/ttyO0 with
{ONLINE|TIME|LATLON|ALTITUDE|STATUS|MODE|PACKET|REPORT}


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